When the sensitivity label applies encryption, the user must have the EXTRACT and VIEW usage rights for Copilot to summarize the data.
User1 - Yes
User1 is Co-Author.
Microsoft 365 co-authors typically have both view and extract permissions when working on documents collaboratively. Co-authors can view and edit the document, and also copy and extract content from it, depending on the specific permissions granted.
User2 - No
A "Reviewer" role generally has view permissions, but not necessarily extract permissions.
Reviewers can typically view the content of documents, files, or other resources, and often can add comments or make tracked changes (depending on the specific implementation and settings). However, they may not have the ability to download or export the content, unless explicitly granted those rights.
User3 - No
User3 has only view permission, not extract permissions.
Note:
If a user is the owner of a sensitivity label and that label is applied to a file, Microsoft 365 Copilot can summarize the file for that user, provided the user also has the necessary usage rights, specifically EXTRACT and VIEW, granted by the sensitivity label, according to Microsoft Learn. If the label includes encryption, these usage rights become crucial for Copilot's ability to access and summarize the content.
Reference:
https://learn.microsoft.com/en-us/copilot/microsoft-365/microsoft-365-copilot-architecture-data- protection-auditing